I had never been so happy to misdiagnose a lesion. The patient was an 88 year-old man who I had known for years, as he is a life-long friend of my mother in-law. When he was examined for a variety of skin lesions, I noted a violaceous patch (or barely raised plaque) on the right forehead extending onto the scalp. I was absolutely convinced he had an angiosarcoma. When the biopsy revealed a low-grade BCL6(+), BCL2(+) follicular center derived B cell lymphoma, I was surprised and relieved. His systemic work-up was negative, thereby defining his lesion a primary cutaneous lymphoma; after consultation with a hematologist/oncologist, a “watchful waiting” approach was opted for, rather than rituximab or radiation – his condition has been stable over the past three years.*
The thought of this being a lymphoma never crossed my mind. Humbled again. I take little solace in knowing that I am not alone. Massone et al report on a series of 13 atypical cases of primary and secondary cutaneous follicle center lymphomas of the head and neck characterized by macular lesions. All patients presented clinically with diffuse, ill defined, partly hypochromic, partly erythematous macules or with inconspicuous lesions located predominantly on the scalp and forehead. Dimension ranged between 4 to 5 cm2 and greater than 30 cm2. The authors stated: “The initial clinical diagnosis was never cutaneous lymphoma, and all patients received various diagnoses including rosacea, androgenetic or scarring alopecia, erysipelas, discoid lupus, Borrelia infection, angiosarcoma, or sarcoidosis” (1).
Primary cutaneous follicle center lymphoma characteristically presents with reddish nodules, plaques, and tumors on the head and neck area, particularly the scalp, and on the back. The same group has previously reported another variant presenting as clustered miliary lesions of the head and neck. With this variant he initial diagnosis was never cutaneous lymphoma either, and all patients had been treated unsuccessfully for different skin conditions including mainly rosacea, lupus miliaris disseminatus faciei, and persistent arthropod bite reaction (2).
Recently a 35-year-old woman presented with a well-defined erythematous plaque with 2 nodules on her right cheek mimicking acne rosacea. Microscopic examination revealed a tumor centered in the reticular dermis and mostly composed of spindle-shaped large B lymphocytes exhibiting bizarre shapes with “boomerang-like” or “spermatozoa-like” appearance. The immunohistochemical staining demonstrated neoplastic lymphocytes positive for CD20, CD79a, and BCL-6, and negative for CD3, CD43, CD10, BCL-2, and MUM-1. These results supported the diagnosis of a follicle center B-cell lymphoma with spindle cells (3).
When reviewing these cases, it’s hard to reach any conclusion other than that cutaneous follicular lymphoma may mimic benign inflammatory or malignant lesions of the head and neck. Keeping this in mind, and having a low threshold of performing a biopsy in atypical cases that are not resolving, is something we teach our first year residents. Each of us need to be reminded of that no matter how many years we have been in practice.
- Massone C, et al. Atypical clinical presentation of primary and secondary cutaneous follicle center lymphoma (FCL) on the head characterized by macular lesions. J Am Acad Dermatol 2016; 75: 1000-6.
- Massone E, et al. Miliary and agminated-type primary cutaneous follicle center lymphoma: Report of 18 cases. J Am Acad Dermatol 2011; 65: 749-55.
- Garrido MC, et al. Primary cutaneous spindle cell B-cell lymphoma of follicle origin mimicking acne rosacea. Am J Dermatopathol 2015; 37: e64-7.
*Patient consent obtained to post his image